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Brocade FabricOS v7.3x is officially supported for IBM clients now. Among all the new features and improvements there are some I would like to cover in small blog entries. Especially for the ones directly related to support and troubleshooting. One command to rule them all Investigating ongoing problems usually starts with setting a baseline. To tell the current problem from the battles of the... [More]

The Storwize V7000 and the SVC (SAN Volume Controller) share the same code base and therefore the same error codes. Many of them indicate a failure condition in this very machine, but there are others just pointing to an external problem source. The error 1370 is one of the second kind. There is not really much information about it in the manuals but in fact it could give you a good understanding... [More]

Sometimes we notice that an ISL is actually a bottleneck in a fabric. Not a congestion bottleneck where the throughput demand is just too high for the ISL's bandwidth. This one could be solved by putting another cable between the both switches. But if you have a latency bottleneck your ISL won't be running at the maximum of the bandwidth. The contrary is the case: it lacks the buffer... [More]

One of the ugliest things that can happen in a SAN is a big performance problem introduced by a slow drain device (or slow draining device). Why is it so ugly? Well, if a full fabric or a full data center drops down - due to a fire for example - it's definitely ugly, too. But such situations can be covered by redundancy (failover to another fabric, to another data center, etc), because the trigger... [More]

Well-made professional education is worth every cent, but in today's world controlled by CFOs everything costing money will be challenged sooner or later. And if you search for freebies you often end up with the first 3-4 sentences of an obviously good book about the topic and the prompt to register with your business information and email address. Weeks of business SPAM will follow then even... [More]

I don't always write technical blog posts. But when I do I make them long and the conclusion contains a request to you my readers to do this or that. I won't do that today. Today is about a behavior I observed, but I won't propose anything. Feel free to draw your own conclusions. Well that might be considered as a proposal :o) This one is about the... [More]

I thought I'd never have to write about fillwords. I thought: there will be a phase of some months and then this topic is dead. Strangely enough it's still alive. I still get questions about them, I still see people blaming them and I still see evitable problems because of changing them. Fillwords? For every new line rate (now read "Generation" or "Gen"), usually... [More]

If you use a SAN Volume Controller it usually is the linchpin of your SAN. Except for the FICON and tape related stuff everything is connected to it. It is the single host for all your storage arrays and the single storage for all your host systems. Because of this crucial role the SVC has some special requirements regarding your SAN design. The rules can be seen in the manuals or in the SVC... [More]

The quality of the data collection is a significant factor for a quick and successful troubleshooting. Here in the remote support it's essential to get the data complete, well prepared, and quickly. Quickly is clear, but what do I mean with complete and well prepared? Collecting data for a Cisco SAN switch case is not difficult if you know what to look for. That depends on the problem. The... [More]

Almost a year ago I wrote an article about congestion bottlenecks in Brocade switches. I said you should avoid them, because they mean that you probably have no redundancy because of too much workload or you don't use it properly. You can use the bottleneckmon to detect them. On the other hand I cared much more about latency bottlenecks , often caused by slow drain devices... [More]